光折变材料中两暗孤子间距离的演化

本文从光折变晶体中能得出暗孤子所满足的演化方程出发,用粒子分析方法得出了两暗孤子相互作用时,其质心间的距离所满足的演化方程。并得出了两暗孤子相互作用势函数的表达式,得到其数值解,并得出如下结论：当两暗孤子间距离△=0时,其相互作用势函数有最小值,表示在光折变晶体中有稳定的暗孤子对,并且相互作用达到最大;当两暗孤子距离△≥5时,其相互作用势函数几乎为零,表示两暗孤子间相互作用很弱,几乎为零。     

电子在半导体多势垒结构中隧穿现象的研究与进展

文中以探索多势垒结构的电子隧穿物理及其器件结构与性能为出发点,论述了多势垒结构隧穿现象的研究与进展。概述了一维半导体异质结构隧穿现象的解析解和数值计算。重点介绍了电子通过半导体双势垒结构产生隧穿现象的研究进展,即电子通过双势垒结构横纵波矢的耦合行为与共振准能级及共振准能级寿命的解析计算。     

激光场中电子被氩原子散射的微分截面研究

应用第二玻恩近似理论，在电子入射方向平行于激光场的极化方向这种特殊的散射模式下，利用光学势模型对激光场中电子一氩原子散射进行了研究。利用静电屏蔽势，分别应用低频近似和第二玻恩近似公式对激光场中电子一氩原子散射进行了计算。和实验相比较，第二玻恩近似方法给出了较好的结果；应用这个较好的理论，利用光学势模型进行了计算，得到了更好的结论。     

Fast Ion Transport in Li-Rich Alloy Anode for High-Energy-Density All Solid-State Lithium Metal Batteries

All-solid-state Li batteries (ASSLBs) with solid-polymer electrolytes are considered promising battery systems to achieve improved safety and high energy density. However, Li dendrite formation at the Li anode under high charging current density/capacity has limited their development. To tackle the issue, Li-metal alloying has been proposed as an alternative strategy to suppress Li dendrite growth in ASSLBs. One drawback of alloying is the relatively lower operating cell voltages, which will inevitably lower energy density compared to cells with pure Li anode. Herein, a Li-rich Li₁₃In₃ alloy electrode (LiRLIA) is proposed, where the Li₁₃In₃ alloy scaffold guides Li nucleation and hinders Li dendrite formation. Meanwhile, the free Li can recover Li's potential and facilitate fast charge transfer kinetics to realize high-energy-density ASSLBs. Benefitting from the stronger adsorption energy and lower diffusion energy barrier of Li on a Li₁₃In₃ substrate, Li prefers to deposit in the 3D Li₁₃In₃ scaffold selectively. Therefore, the Li–Li symmetric cell constructed with LiRLIA can operate at a high current density/capacity of 5 mA cm⁻²/5 mAh cm⁻² for almost 1000 h.     

类W-势阱与应变超晶格量子阱的带间跃迁

假设量子阱是类W-势阱,应变效应表现为势阱底部出现了类抛物线鼓包。在量子力学框架下,讨论了应变效应对输出波长的影响。结果表明,在应变作用下,量子阱出现了能级分裂,正是这种分裂为高性能量子阱光学器件的研制提供了更大的设计空间,为量子阱激光器件输出波长的调节提供了理论基础。     

A theoretical study of the performance of sub-micron MOSFET devices in the presence of edge potential

In the present communication we have presented a detailed theoretical analysis of the performance of the sub-micron device in the presence of the discontinuity at the Si–SiO₂ interface. It is assumed that due to interface discontinuity a potential develops at the edges (Source/Drain) in addition to the built-in-potential. This potential, called Edge Potential, measures directly the extent of the interface roughness. The effect of this potential is more critical in the case of short channel device where drain and source are in close proximity. Our analysis shows that the discontinuity is dominant at the edges but not in the channel. Drive current as well as saturation transconductance decreases in the presence of edge potential. These results suggest that the performance of the device degrades due to the interface roughness. Effect of interface roughness near the edges can be reduced at high gate voltage but it will result more interface roughness scattering.     

Cu掺杂CaCu_3Ti_4O_(12)陶瓷的介电性能和晶界特征

采用传统的固相反应工艺制备了Cu掺杂的CaCu3Ti4O12(Cu-CCTO)陶瓷。采用Schottky热电子发射模型研究了其晶界特征。研究了保温时间对Cu-CCTO陶瓷的介电性能和晶界特征的影响。结果表明:保温时间从1 h延长到30 h,Cu-CCTO陶瓷在100 kHz下的介电损耗保持在0.135,相对介电常数由3 600增至20 000以上。随着保温时间的延长,Cu-CCTO陶瓷的I-V非线性系数由1.8增至3.37,但击穿电场强度却由1 500 V/cm降至约700 V/cm。随着保温时间的延长,Cu-CCTO陶瓷的势垒高度和耗尽层宽度均增加。     

Three‐Dimensional Kelvin Probe Microscopy for Characterizing In‐Plane Piezoelectric Potential of Laterally Deflected ZnO Micro‐/Nanowires

Potential characterization of deflected piezoelectric nanowires (NWs) is of great interest for current development of electromechanical nanogenerators that harvest ambient mechanical energy. In this paper, a Kelvin probe microscopy (KPM) technique hybridizing scanning KPM (SKPM) with atomic force microscope (AFM) surface‐approach spectroscopy methods for characterizing in‐plane piezoelectric potential of ZnO microwires (MWs) is presented. This technique decouples the scanning motion of the AFM tip from sample topography, and thus effectively eliminates artifacts induced by high topographical variations along the edges of MWs/NWs which make characterization by conventional SKPM inappropriate or impossible. By virtue of the topography/tip motion decoupling approach, the electrical potential can also be mapped in a three‐dimensional (3D) spatial volume above the sample surface. Therefore, this technique is named 3DKPM. Through 3DKPM mapping, the piezopotential generated by a laterally deflected ZnO MW was determined by extracting the potential asymmetry from opposite sides of the MW. The measurement results agree well with theoretical predictions. Integrating an external bias to the MW sample allowed direct observation of piezopotential and carrier concentration coupling phenomenon in ZnO, opening a door toward quantitative microscopic investigation of the piezotronic effect. With further positioning refinements, 3DKPM could become a powerful technique for the characterization of piezoelectric potential and related effects in micro/nanostructures of high topographical variations, as well as development of MW/NW‐based piezoelectric nanodevices.     

Giant traps on the surface of hydride vapor phase epitaxy-grown free-standing GaN

Extended defects on the top surface of a 250-μm-thick free-standing GaN sample, grown by hydride vapor phase epitaxy (HVPE), were studied by deep level transient spectroscopy (DLTS) and scanning surface potential microscopy (SSPM). For comparison, similar studies were carried out on as-grown HVPE-GaN samples. In addition to the commonly observed traps in as-grown HVPE-GaN, the DLTS measurements on free-standing GaN reveal a very high concentration of deep traps (∼1.0 eV) within about 300 nm of the surface. These traps show nonexponential capture kinetics, reminiscent of those associated with large defects, that can accumulate multiple charges. The SSPM measurements clearly reveal the presence of charged microcracks on the top surface of the sample. It appears that the “giant traps” may be associated with these microcracks, but we cannot rule out the involvement of other extended defects associated with the near-surface damage caused by the polishing/etching procedure.     

Tribotronics for Active Mechanosensation and Self‐Powered Microsystems

Tribotronics has attracted great attention as a new research field that encompasses the control and tuning of semiconductor transport by triboelectricity. Here, tribotronics is reviewed in terms of active mechanosensation and human–machine interfacing. As a fundamental unit, contact electrification field‐effect transistors are analyzed, in which the triboelectric potential can be used to control electrical transport in semiconductors. Several tribotronic functional devices have been developed for active control and information sensing, which has demonstrated triboelectricity‐controlled electronics and established active mechanosensation for the external environment. In addition, the universal triboelectric power management strategy and the triboelectric nanogenerator‐based constant sources are also reviewed, in which triboelectricity can be managed by electronics in the reverse action. With the implantation of triboelectric power management modules, the harvested triboelectricity by various kinds of human kinetic and environmental mechanical energy can be effectively managed as a power supply for self‐powered microsystems. In terms of the research prospects for interactions between triboelectricity and semiconductors, tribotronics is expected to demonstrate significant impact and potential applications in micro‐electro‐mechanical systems/nano‐electro‐mechanical systems (MEMS/NEMS), flexible electronics, robotics, wireless sensor network, and Internet of Things.